Rapidly growing Mega-Church needed entire infrastructure overhaul and was adding several hundred thousand square feet of new space to its campus. We were able to solve all of their technology challenges.

I have 2 servers, we'll call them TheServer (sql & file) & TheClient (RDS), both running Win 6.1.7601 x64. Both using teamed BroadCom Nics - same driver version. both using the same TCP global parameters (netsh interface tcp show global). Both are on the same GBit switch. TheServer has 3 teamed interfaces, TheClient has 2 teamed interfaces.

If I send a 300mb file from TheClient to TheServer, I barely have time to see a 200MB/sec transfer rate. Beautiful! If I send the same file back from TheServer to TheClient, i get to look at 40-120 KB/sec for a long time. Yes, you read that right: it says KB on one and MB on the other. The difference in speeds is a factor of over a thousand.

There are no firewalls, and on these servers Antivirus only scans executing code. I get the same behavior without regard to which machine the transfer was initiated on.

8 Replies

I would verify the settings are correct on all the NICs, sounds to me like you've got one set for half-duplex or something weird like that. Have you run any tests on the servers to verify that they are both set up right? I would check each one individually if you can and see if one or the other has an issue.

I agree with @RobertFranz, break the team and see if the same issue is with both NICs, you could also setup the second nic with a separate static IP and try sending the file from one nic to the other thus ruling out any external interface issue.

if you copy from one RDS session to another is the file transfer equally slow?

t the time of the test, the only user on either machine was me. Everyone else was home... I was on the console of both servers as the domain admin at the time of the test, so i doubt that session difficulties are to blame.

HD IO is very fast on both machines - TheClient has a 3 drive RAID 5, TheServer has a RAID 10 dedicated to data & a RAID 1 OS drive. All the drives are at least 10k SAS.

I wrestled with what I thought was a flaky router for a good bit of time before I realized that after about 5 minutes, the connector was backing out of the port just enough to kill data, but not enough to lose the link light.